1. Field Of The Invention
This invention relates to a wiping device which wipes a windshield of an automobile or the like to remove raindrops, dust and the like on it, and in particular to a wiper linkage of the cross arm type which is used with a mechanism of the single-arm type wiper having a single wiper blade.
2. Description of the Prior Art
Heretofore, there has been used a wiper linkage of the cross arm type which is known under the name of Tschebyscheff's cross link device.
Namely, the wiper linkage of the cross arm type described above is shown in FIGS. 5 to 9.
In the figures, a driving rod is indicated with numeral 100, numeral 101 designates an idler having an idle arm 101a, numerals 102 and 103 designate cross arms and numeral 104 designates a lever having a pivot shaft 105.
Said cross arms 102 and 103 are provided with coupling bases 102a, 102b, 103a and 103b made of synthetic resin and located at opposite ends thereof as shown in FIG. 7.
In the coupling of said cross arm 102 with said driving rod 100, a coupling pin 107 is put through the coupling base 102b and an interposed wave washer 106, and flattened firmly against the driving rod 100 as shown in FIG. 8 and FIG. 9.
Also in the coupling of the cross arm 103 with the driving rod 100, the coupling pin 107 is flattened firmly against the driving rod 100 through the wave washer 106 in the same manner as said cross arm 102.
In the coupling of the cross arms 102 and 103 with the lever 104, coupling pins 107 and 107 are put through coupling bases 102a and 103a and interposed wave washers 106 and 106, and flattened firmly against both ends of the lever 104.
Namely, at both ends of the lever 104 having the pivot shaft 105, each of cross arms 102 and 103 is connected by plane linking. The cross arms 102 and 103 are also connected by plane linking in the coupling with driving rod 100. The driving rod 100 is connected by plane linking to the idler 101 in the same manner as described above.
Therefore, the dimensional error in the couplings between the lever 104 and the cross arms 102, 103 or the cross arms 102, 103 and the driving rod 100 is absorbed by the wave washers 106.
However, in the conventional wiper linkage of the cross arm type as described above, it is very complicated to assemble because the couplings of the lever 104 with the cross arms 102 and 103 or the cross arms 102 and 103 with the driving rod 100 are connected by plane linking by flattening the ends of the coupling pins 107 firmly. There is a problem since there is a limit in the maximum allowable error due to the dimensions of the wave washer 106 because the dimensional error absorption at said coupling part connected by plane linking is obtained by the wave washer 106.
Considering the waterproof property of the respective coupling parts, it is necessary to waterproof at the upper and lower sides of respective coupling bases 102a, 102b, 103a and 103b shown in FIG. 7 and therefore it is a problem since such a waterproof structure becomes very complicated.